1. Field
The present invention relates to a scan driver and an optical compensation method and driving method for an organic light emitting display device.
2. Description of the Related Art
An organic light emitting element used for an organic light emitting display device is a self-light emitting element which has a light emitting layer formed between two electrodes. In the organic light emitting display device, electrons and holes are injected into the light emitting layer from a electron injection electrode and a hole injection electrode, respectively. The injected electrons and holes are combined to generate excitons, which illuminate when converting from an excited state to a ground state.
In the organic light emitting display device, when scan signals, data signals, and power are supplied to a plurality of subpixels arranged in a matrix, selected subpixels emit light, to display images. Some organic light, emitting display devices have a subpixel structure (hereinafter, abbreviated as RGBW OLED) that includes red, green, blue, and white colors.
The RGBW OLED uses a complicated algorithm (which is equivalent to finding one point on a three-dimensional space) that adjusts three RGB gains. The relationship between gain and luminance of each of RGBW has a different increasing pattern for each gray level, so it is difficult to estimate the common amount of change for converging on target values. Therefore, there is a high possibility of deadlock caused by gain variations because the RGBW OLED commonly uses RGBW gains to adjust color coordinates and luminance.
Moreover, the RGBW OLED drives one of the RGB subpixels to additionally emit light on a display panel in order to correct white coordinates. Accordingly, the power consumption of the RGBW OLED increases as much as the color additionally emits light on the display panel.